Apparatuses for packaging pourable food in containers comprise a number of units for performing a number of steps. In short, such an apparatus may comprise the steps of forming a tube of a web of packaging material, forming sleeves from the tube by transversally sealing one end of the tube and/or cutting the tube, folding containers from said sleeves to their intended final form, filling said containers with the pourable food, and finally sealing the other end of the containers. The second opening sealing step, i.e. the step of finally sealing the container, is performed when the containers are in horizontal movement. Further, the folding step can be divided into a number of sub-steps. For example, during a first folding sub-step, performed in association to the sealing step, a section of a sleeve/container being sealed may be formed to have a rectangular cross-section. In a second folding sub-step, the sleeve/container may be folded in such a way that a rectangular base is achieved, e.g. by folding the outer ends of the sealing end into the middle of the sealing.
In the sealing steps two sealing jaws may be arranged on opposing sides of the sleeve. Reciprocating movement of the sealing jaws may then create a seal transversally in respect of the longitudinal axis of the sleeve. To ensure the obtainment of a secure and tight seal and to avoid unnecessary wear on the equipment, such as the sealing jaws, or bearings, gears, etc, affected by the movement of the sealing jaws, one wishes to make sure that the sealing jaws are parallel to each other during the reciprocating movement, and especially during the interaction between the two.
It is known within the field of a vertical flow path of containers, such as in U.S. Pat. No. 2,606,412, U.S. Pat. No. 3,245,197, and U.S. Pat. No. 6,138,442, to use guide rods arranged transversally to the longitudinal extension of the sealing jaws. These guiding rods are driven by the same end motor, which means that a motor position error, e.g. due to mechanical wear, or synchronization errors between several motors induces high strain on the system and the guiding rods, resulting in fast wear. These guide rods also run through the sealing jaws, such that the sealing jaws necessarily are kept in the same plane during the entire rotational cycle, with respect to each other. In systems wherein the sealing jaws are intended to also oscillate in the vertical plane, the strain on the guide rods will be high, resulting in fast material wear and thus more frequent stops in the production and exchange of parts. As a consequence of the position of these guide rods, there will also be a need of demounting the entire sealing apparatus to perform maintenance on or exchange of the guiding rods. Also, since the guide rods run through the sealing jaws the guide rods will wear on the sealing jaws, bringing about a more frequent exchange of the expensive sealing jaws. Furthermore, the sealing pattern of the sealing jaws is affected or limited, and it will be impossible to transport containers, sleeves, tubes, webs, etc in a horizontal and longitudinal direction, without the need of complicated elevating or lowering actions of the sealing jaws and/or the containers, sleeves, tubes, webs, etc, since the guiding rods will be in the pathway.
Hence, a new apparatus for sealing containers in horizontal movement would be advantageous, and especially an apparatus allowing for parallel alignment of sealing jaws, while simultaneously providing a durable and high resistant alignment system, decreasing wear on material, increasing productivity, alleviating exchange of parts, decrease wear on the sealing jaws, and decreasing the limitation on possible sealing patterns and/or areas.